The invention provides a freeze-dried composition of mycophenolate mofetil. The freeze-dried composition of mycophenolate mofetil is mainly composed of the active component mycophenolate mofetil, a stabilizing agent, a cosolvent, a pH regulating agent and injection water. The freeze-dried composition of mycophenolate mofetil is in the shape of a loose block, can be rapidly dissolved after addition of water, has good dissolvability and is free of shrinkage after long-term preservation; and freeze-drying time is short, so production cost is greatly reduced.